Dryer for photographic prints and the like

ABSTRACT

A dryer intended for the drying of prints consisting of a photographic emulsion on a paper backing and particularly where the printing paper is of the resin-coated or &#39;&#39;&#39;&#39;RC&#39;&#39;&#39;&#39; type. The prints are fed into the entryway of a box-like frame or enclosure where they first encounter a pair of driven &#39;&#39;&#39;&#39;squeegee&#39;&#39;&#39;&#39; rollers. The upper squeegee roller, which contacts the emulsion side, is constantly wiped, over its entire length, by a wet sponge for insuring that the roller contacting the emulsion is wet when it begins to act upon the face of the print and for insuring that the roller remains clean and perfectly free of deposits. The upper squeegee roller and cooperating sponge are mounted in a removable cartridge which is received in the upper portion of the enclosure. A belt assembly formed of a set of laterally spaced driven belts transports the prints through the machine. The upper portion of the enclosure, having an associated blower and heating element, blows heated air downwardly upon the face of the prints during transport. At the rear end of the belt assembly the print is reversed through 180* for discharge of the dried prints forwardly upon the top of the machine. The two portions of the enclosure are hinged so that the squeegee rollers are biased together during use but capable of swinging apart for removal of the cartridge and to provide access to the interior.

United States Patent Kallenberg DRYER FOR PHOTOGRAPHIC PRINTS AND THE LIKE [75] Inventor: Karl J. Kallenberg, Minneapolis,

' Minn.

[73] Assignee: jApeco Corporation, Evanston, Ill.

[22] Filed: Nov. 17, 1971 i [21] Appl.No.: 199,504

[52] U.S. Cl. 34/70, 34/80, 34/155,

- 34/160 [51] Int. Cl. F26b 19/00 [58] Field of Search 34/70, 71, 80, 95,

[56] References Cited UNITED STATES PATENTS 3,548,512 12/1970 Smoot 34/70 3,330,189 7/1967 Vil 3,308,555 3/1967 Kruger.... 2,882,611 4/1959 Debrie 3,071,866 1/1963 Mangus 3,448,528 6/1969 Jackson et al. 34/95 Primary ExaminerWilliam F. ODea Assistant Examiner-James C. Yeung Attorney-Wolfe, Hubbard, Leydig, Voit & Osann June 19, 1973 [57] ABSTRACT A dryer intended for the drying of prints consisting of a photographic emulsion on a paper backing and particularly where the printing paper is of the resin-coated or RC type. The prints are fed into the entryway of a box-like frame or enclosure where they first encounter a pair of driven squeegee rollers. The upper squeegee roller, which contacts the emulsion side, is constantly wiped, over its entire length, by a wet sponge for insuring that the roller contacting the emulsion is wet when it begins to act upon the face of the print and for insuring that the roller remains clean and perfectly free of deposits. The upper squeegee roller and cooperating sponge are mounted in a removable cartridge which is received in the upper portion of the enclosure. A belt assembly formed of a set of laterally spaced driven belts transports the prints through the machine. The upper portion of the enclosure, having an associated blower and heating element, blows heated air downwardly upon the face of the prints during transport. At the rear end of the belt assembly the print is reversed through 180 for discharge of the dried prints forwardly upon the top of the machine. The two portions of the enclosure are hinged so that the squeegee rollers are biased together during use but capable of swinging apart for removal of the cartridge and to provide access to the interior.

25 Claims, 17 Drawing Figures PATENIEU JUN 1 91915 DRYER FOR PHOTOGRAPIIIC PRINTS AND THE. LIKE A print coming from the final washing bath following the process of development is normally quite wet, with the paper backing being saturated and with beads of water standing on the emulsion side. It is customary in drying such a print to pass it between a pair of resilient squeegee rollers which express the excess water into a drip pan or the like. The so called RC or resin-coated photographic paper presents a special drying problem for a number of reasons. Primarily, the paper includes a chemical stabilizer which is quite sticky prior to the time that the paper reaches its fully dried condition. Moreover, the paper backing, being plasticimpregnated, tends to absorb only a limited amount of moisture during the processing and washing steps. Consequently, there is risk that when the paper is inserted into the dryer there will be no excess of moisture along the leading edge to form a puddle at the nip to insure that the paper will be separated from the roller surface by a protective film. Where the paper is nearly dry and is brought into direct contact with a dry squeegee roller, the stabilizing material may tend to lift off or offset" onto the surface of the squeegee roller. A portion of the soft emulsion may also lift ofl. This not only produces an unwanted buildup upon the roller surfaces but tends to destroy the gloss on the emulsion side of the print, particularly the portion adjacent the leading edge.

It is, accordingly, an object of the present invention to provide a dryer having a pair of squeegee rollers which preserves the integrity of the print and which prevents any accumulative build-up on the roller surfaces evenfiafter many hours of continuous operation. It is a related object to provide a dryer which is capable of handling prints having a wide range of moisture content, all the way from the saturated condition, with standing beads of water, to the nearly dry condition while producing a uniform final result. It is a further related object to provide a print dryer having a pair of squeegee rollers in which the roller contacting the emulsion side is constantly maintained in a uniformly wetted condition and constantly wiped clean so that the roller surfaces are in the same fresh condition at the end of a busy work shift as at the beginning.

It is a related object to provide a squeegee assembly in which one of the squeegee rollers is mounted in a cartridge containing a wetted sponge and which cartridge may be cleaned and recharged simply by flushing under a water tap. It is an object of the invention in one of its aspects to provide a cartridge for supporting and constantly cleaning and wetting a pair of squeegee rollers in a print dryer, the cartridge being so constructed and arranged as to be easily and quickly removed from the machine and easily disassembled for flushing the sponge and for recharging it with water.

It is another object of the present invention to provide a print dryer in which the prints leaving the squee gee rollers, and of uniform dampness, are efficiently acted upon by a wann air stream which impinges directly upon the face of the prints as they are transported horizontally within the machine and in which the dried prints are discharged at the top of the machine for easy and convenient removal. It is, therefore, an object of the invention to provide a print dryer which is easily operated, even by inexperienced personnel, which does not subject the prints to risk of damage during the drying process and which permits the drying time to be safely minimized. It is a related object to provide a dryer which transports the prints positively and in succession but which avoids engagement with the emulsion side during the drying process.

It is a general object of the present invention to provide a print dryer which is highly compact, which may be conveniently supported on a bench or work table, which is inherently economical, and which may be used universally to dry prints of the RC type as well as prints formed of other or more traditional materials and in various weights or thicknesses. It is, moreover, an object to provide a print dryer in which the upper and lower portions are hinged together and in which the upper portion may be swung clear of the lower for access when inspection or servicing become necessary.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings in which:

FIG. 1 is a perspective view of a drying machine constructed in accordance with the present invention and with a print feeding into the entryway.

FIG. 2 is a vertical section taken longitudinally through the machine shown in FIG. 1.

FIG. 2a is a fragmentary cross section taken through the hinge along line 2a-2a in FIG. 2.

FIG. 3 is a fragmentary and foreshortened horizontal section showing the belt assembly and taken along the line 3-3 in FIG. 2.

FIG. 3a is a fragmentary section showing a typical roller profile taken along line 3a-3a in FIG. 3.

FIG. 4 is a perspective view showing the arrangement of belts in the turnaround at the rear of the machine.

FIG. 5 is a fragmentary vertical section looking along the line 5-5 in FIG. 2.

FIG. 6 is a fragmentary section looking in the direction of the heater and blower assembly along the line 6.-6 in FIG. '2.

FIG. 7 shows the profile of the squeegee roller cartridge constructed in accordance with the invention but somewhat foreshortened.

FIG. 8 shows the end view of the cartridge of FIG. 7.

FIG. 9 is a cross section taken through the sponge looking along the line 9-9 in FIG. 7.

FIG. 10 is an exploded view on a reduced scale of the parts making up the cartridge of FIG. 7.

FIG. 11 is a perspective view showing the upper portion of the dryer propped at an angle and partial retraction of the drop tray prior to release of the cartridge.

FIG. 12 shows the withdrawal of the cartridge.

FIG. I3shows the cartridge being disassembled for flushing. I

FIG. 14 shows flushing under a tap with the sponge in its enclosing shell.

FIG. I5 is a perspective view showing the upper portion of the dryer fully upraised for access.

While the invention has been described in connection with a preferred embodiment, it will be understood that I do not intend to be limited to the particular embodiment shown but intend, on the contrary, to cover the various alternative and equivalent constructions included within the spirit and scope of the appended claims.

Turning now to the drawings and particularly to FIGS. 1 to 3 there is shown a dryer 20 constructed in accordance with the present invention having a lower hollow base portion 21 and a hollow upper portion 22, the two portions together forming a box-like enclosure. Between the lower and upper portions is an entryway 23 into which a print I is fed, face-up between a lower squeegee roller 24 and an upper squeegee roller 25, the nip between them being indicated at 26. The squeegee rollers serve to squeeze from the print any excess moisture, for example, in the form of standing drops of water, following which the print is subjected to warm currents of air directed downwardly upon the face of the print as the print is in motion and with the print being discharged within a short time interval from a forwardly facing discharge opening 27, the print being deposited upon a flat receiving surface at the top of the machine.

In accordance with the present invention a belt assembly is provided in the hollow base portion of the machine for supporting a print face-up, while the upper portion of the machine serves as a plenum which is connected to a source of heated air and which has openings in its bottom wall for discharging air downwardly against the print for the purpose of removing moisture and for pressing the print against the belts of the belt assembly for positive transport from one end of the machine to the other. As shown in FIGS. 2 and 3, the belt assembly, generally indicated at 30, has a first set of belts 31 and a second set of belts 32. At the forward end of the assembly, and generally alined with the nip between the squeegee rollers, is a belt roller 33 mounted upon suitable bearings and having integral annular ridges for the individual belts (see FIG. 3a). Spaced midway in the machine is a second roller 34 about which both sets of belts are trained, the belts being laterally spaced from one another and interdigitated on the roller. Finally, the belts in the set 32 are trained about a roller 35 which is coupled, by means of a belt 36 to a belt drive motor 3'7. As will be seen, the spacing between the belts permits sufficient open area for wann air to circulate around and under the prints as they are being transported.

For the purpose of directing air downwardly upon the prints, the upper portion 22 of the dryer is of hollow box shape defining a plenum 40 having a bottom wall 41, a top wall 42, a front wall 43 and a rear end 44 which is open and which serves to admit warm air under slight pressure. The plenum is enclosed by side walls 45. For supplying warm air to the plenum, a blower assembly 50 is provided made up of blowers 51, 52 (FIG. which are arranged on opposite sides of a drive motor 53. The blowers are per se conventional, taking air from a region adjacent the shaft and expelling it under pressure through respective discharge orifices 55, 56. The air is discharged into an antechamber 60 having heating elements 61, 62 for warming the air, following which the air is discharged into the plenum. The antechamber 60 provides an air passage from the blower assembly to the plenum, and to this end the mouth 64 of the chamber registers with, and is closely fitted to, the rear end 44 of the plenum (see FIG. 5). For the purpose of discharging the air downwardly from the plenum, the bottom wall 41 is formed with transversely extending slot openings 70 which are about equally spaced above the run of the belt assembly. It is preferred to arrange the two sets of belts 31, 32 in shallow V formation and to form the bottom wall of the plenum, as shown, into a similar shallow -V. The air from the orifices 70 impingeing upon the faces of the prints produces rapid drying action while at the same time holding the prints down securely upon the belt. In this way the prints are positively and reliably transported without necessity for touching the face or emulsion side.

In carrying out the invention, the upper portion of the dryer is preferably double walled, having a top wall 72 and a front wall 73 which are separate and spaced from the top and front walls 42, 43 which define the plenum. In this way the top and front surfaces of the machine remain cool to the touch, even though the air emanating from the heaters 61, 62 is at an elevated temperature. Preferably the space between the walls is filled with rigid insulation. In accordance with one of the main features of the invention the lower squeegee roller 24 is mounted in the lower portion of the dryer and constantly rotated while the upper squeegee roller is mounted in the upper portion of the dryer and engages a wiper having a porous reservoir saturated with water in the form of a sponge which extends along the length of the roller, the sponge serving to keep the roller clean and uniformly wetted in readiness for insertion of a print through the entryway 23 and into the nip 26 of the rollers. More specifically in accordance with the invention a squeegee roller cartridge is provided in the upper portion of the machine which is of elongated rectangular shape and which serves to hold the upper squeegee roller and the sponge in engagement with it, the cartridge being manually retractable for periodic cleaning of the sponge and renewal of the water supply. Thus, referring to FIGS. 7-10 of the drawings in addition to FIG. 2, there is disclosed a cartridge having a central recess 81 which is substantially fully occupied by a sponge 82 having a lower or working edge 83 which is in wiping engagement with the surface of the squeegee roller 25. The cartridge has an outer housing which is formed of a pair of side plates 91, 92 having respective flanges 93, 94 along the upper edge and end flanges 95, 96 at the respective ends. When the side plates are fitted together face-to-face, and with the edges of the flanges in engagement, a rectangular boxlike housing is formed which may be conveniently inserted into seated position in the upper portion of the dryer. For the purpose of maintaining the sideplates 91, 92 in endwise alinement, small flat guide plates 97 are secured to the end flanges held in place by machine screws 98 or the like. The side plates are preferably made identical with one another with one guide plate 97 on each of them.

For the purpose of supporting the squeegee roller 25 integrally within the cartridge for proper wiping engagement by the sponge, the cooperating end flanges have complimentary notches which encircle bearings at the ends of the squeegee roller. Thus the squeegee roller is provided with captive cylindrical bearings 100 at the respective ends which are engaged between complimentary notches 101, 102 formed in the end flanges 95,96 of the cartridge housing. When it is desired to disassemble the housing, the side plates 91, 92 are removed which separates the notches, permitting the squeegee roller 25 to drop free and also freeing the sponge 82.

In accordance with one of the aspects of the invention the sponge 82 is enclosed by a thin shell formed of metal or the like, the shell being provided in two cooperating pieces which, together, enclose the sponge to inhibit evaporation, but which have side walls which occupy a normal spacing but which are nevertheless squeezeable toward one another. Thus as shown in FIG. the shell structure, indicated at 110, is made up, of two pieces 111, 112. The piece 112 has a side wall 113, an upper wall 114 having a flange 114a, and a lower wall 115. The cooperating piece has a side wall 116, end walls 117, and end wall flanges 1117a. The two portions 111, 112 of the shell thus totally enclose the sponge except for the working edge 83 of the sponge which is projectingly exposed. When the shell is assembled the flange 114a is slipped over the edge of the wall 116 and the flanges 117a are slipped over the ends of the opposite wall 113. The sponge is preferably made of cellulose which is quite resilient in the wet condition and which, in its relaxed wet state, is dimensioned to occupy the full thickness dimension of the shell 110, thereby seating the flanges 114a, 117a. However, when it is desired to flush any residual water out of the sponge, the shell and its contained sponge are removed from the housing and the walls 113, 116 are squeezed together thereby compressing the sponge to expel the stale or spent water. To enable pressing the sponge uniformly along its length, the walls of the shell, while thin, are nevertheless relatively stiff. When pressure on the sidewall 113, 116 is released, and while the sponge is being bathed with water under a tap, a fresh charge of water is sucked into the sponge and the sponge is restored to its normal condition as shown in FIG. 8. The sponge assembly may be removed from the source of water while the sides are still partially squeezed together, thereby to control the amount of water which is sucked in.

For the purpose of receiving the cartridge 80 and for holding it in position within the upper portion of the dryer, a receptacle 120 is provided as shown in FIGS. 2 and 6. Such receptacle is formed of a front plate 121 and a back plate 122 with a channel or bridging member 123 defining a receiving space 124. The back plate is preferably mounted upon a hinge 125 (see FIG. 2) and has a pair of leaf springs 126 which press against the wall of the plenum tending to rock the receptacle clockwise as shown in FIG. 2 to bring the upper squeegee roller 25 into resilient biased engagement with the lower squeegee roller 24. The amount of forward rocking movement is limited by a stop structure which includes a lip 127 on the front receptacle plate 121 which engages with an inwardly turned lip 128 which is integral with the front wall 73 and which defines the upper edge of the entryway. In effect, the cartridge is mounted for limited movement toward and away from the cooperating squeegee roller 24 with the spring 126 biasing the cartridge downwardly. This insures that pressure will be applied equally along the length of the squeegee roller.

For the purpose of maintaining the cartridge 80 fully seated, or bottomed within the receptacle 120, the receptacle is provided with a pair of retention clips 131 each of which is secured to the receptacle structure by machine screws 132 or the like, and each of which has an inwardly turned retaining lip 133 and a downwardly projecting tang 134. To remove the cartridge 80 from the receptacle 120 the retaining clips 131 must first be retracted (pulled forwardly) using fingertip pressure. Turning attention to the lower squeegee roller 24, which is suitably journaled in the base, constant rotation of the roller is achieved by coupling it to roller 33 by a series of spur gears 135, 136, 137.

In accordance with one of the important features of the present invention the upper portion 22 of the dryer is hinged at its rear end about a horizontal hinge axis so as to permit the portion 22 to be swung upwardly, either through a limited angle sufficient to permit retraction of the cartridge downwardly from the receptacle, or through a large angle, on the order of to fully expose the interior of the dryer for purposes of service or inspection. More'specifically in accordance with the invention, the lower portion of the dryer is provided with a pair of upstanding parallel side walls, between which the upper portion or plenum is hinged about a transversely extending axis and flushly recessed in normal, horizontal working position in which the rear end 44 of the plenum is in direct communication with blowers 51, 52 and their heaters 61, 62. The hinge, indicated at (FIG. 2), is so located, at the rear of the plenum and adjacent its top surface, to permit the plenum to be swung through an angle which is on the order of, and preferably in excess of, 90 to the position shown in FIG. 15, which exposes the space above the belt assembly 30 and between the side walls 141, 142. The side walls preferably have upper edges 143, 144 which are flush with the receiving surface 28 when the upper portion of the dryer is in its horizontal working position. The hinge 140 may take any desired form; for example, it may consist of a pair of alined stubshafts, or trunions, 145 which are received within cooperating bearings 146 (see FIG. 2a).

In order to hold the upper portion of the dryer cocked upwardly at a slight angle for removal of the cartridge, a prop is provided within the side walls, swingable between a generally vertical propping position and a horizontal storage position. Such a prop, indicated at 147, is pivoted for swinging movement about a pivot 147a with stops 148, 149 to establish the propping and storage positions, respectively. The prop 147 keeps the upper portion 22 safely upraised as shown in FIGS. 11 and 12 for release and withdrawal of the cartridge 80.

When the upper or plenum portion is swung upwardly from its horizontal position, the flow passage from the blower assembly is broken. It should be noted that when the plenum is raised, the blower assembly and heater all remain stationary and only the air passage from the blower assembly is interrupted. When the plenum is subsequently restored to its horizontal position, the rear end of the plenum is swung into register with the mouth 64 of the chamber 60 which provides a direct connection for the flow of air from the blower assembly.

In accordance with one of the aspects of the invention a turnaround is provided at the rear end of the belt assembly 30 for the purpose of engaging the prints in the dry condition for turning them through an angle of substantially l80 for discharge forwardly upon the receiving surface 28. More specifically in accordance with the invention, the lower portion of the dryer is provided with an integral superstructure which extends above the discharge surface 28 for housing the blower together with turnaround guide surfaces and an associated belt assembly. Thus as shown in FIG. 2, the superstructure, indicated at 150, is formed by making the side walls 141, 142 of L shape extending them up wardly at their rear ends as shown at 141a, 142a. The superstructure is topped by a cover 151 which extends rearwardly, and then downwardly, to a hinge 152. Ad

mission of air to the blowers occurs through openings 143 in the superstructure, while discharge of the moist air from the prints occurs through louvered openings 144 in the back of cover 151. Discharge also takes place forwardly past the drip tray 190 which is preferably pulled out an inch or two during operation of the dryer.

For transporting the prints around the blower assembly and into the superstructure, a turnaround 160 is used having a cylindrical guide plate 161. Trained around the guide plate are a set 162 of outer" belts which encircle the roller 35 at the lower end, passing upwardly about the outer surface of the plate 161. At the upper end the belts make a 180 about an idler 164, with the loop being completed by passing the belts 162 about idler rollers 165, 166 and 167 back to the drive roller 35.

For engaging the inner surface of the print, a second or inner set of turnaround belts is used which also pass around the guide plate 161. These belts, indicated at 172 are powered by a roller 171 at the lower end which drives the belts along a pass 173, thence around the guide 161 to an idler roller 174 at the upper end adjacent the discharge opening. The return pass of the belts 172 occurs about an auxiliary guide plate 175 which lies within and generally concentric with the cylindrical guide plate 161 previously mentioned. The two sets of the belts 162, 172 working together, provide a nip 176 which receives the leading edge of a print fed from the belt assembly 30. By the time that the print reaches the nip 176, the emulsion on the face of the print has been sufficiently dried so that the face, as well as the back surface, may be securely gripped between the belts for turnaround purposes. For driving the inner set of belts 172 a drive belt 180 is provided which is powered by passing it around the end of the roller 35 and thence around idler pulleys 181, 182. The pulleys are so arranged that they form a loop 183 engaging the end of the roller 171 for driving the latter in a clockwise direction.

In short, then, when a print, which has been dried on the sets of belts 31, 32 reaches the roller 35 in the rear of the machine, the print is engaged between the sets of belts 162, 172 and passed around the cylindrical guide plate 161 to make a 180 turn, with the print being finally discharged between the rollers 164, 174 at the discharge orifice 27 for depositing upon the receiving surface 28. The prints collect upon this surface in a neat pile until intentionally removed. The fact that the upper surface 28 of the upper portion of the dryer is flush with the upper surface 143, 144 of the side walls not only makes for an attractive appearance but provides a smooth and unobstructed receiving area.

In order to collect any drippage of water from the squeegee rollers 24, 25 and to permit the accumulated moisture to be evaporated by stray currents of warm air during the drying process, thereby to minimize the need for frequent emptying, a drip tray 190 is provided in the base of the machine, extending from a front edge 191 to a rear edge 192. The drip tray is dimensioned to be received in the lower portion of the machine in "drawer-like fashion, occupying substantially the full width of the base, with the front edge 191 of the "drawer having an upwardly extended front panel as indicated at 193 which encloses the front of the machine up to the level of the entryway.

In readying the machine for operation, the front panel 193 of the drip tray is pulled outwardly to the position shown in FIG. 11. The upper portion 22 of the dryer is then swung upwardly about its hinge 140, separating the squeegee rollers and providing access for the operator to swing the prop 147 forwardly against the stop 148 thereby to prop the upper portion of the dryer in the upwardly angled position shown.

The tangs 134 on the release members 131 (FIG. 6) are urged forwardly with fingertip pressure, thereby releasing the cartridge so that it may be withdrawn forwardly and downwardly as shown in FIG. 12. The side plate 92 (see FIGS. 8 and 13) is removed to free the squeegee roller 25, and the sponge within its shell is removed. The sponge assembly is held, with the edge 83 of the sponge extending upwardly, under a water tap as shown in FIG. 14, and the sides of the shell are slowly squeezed and released so that the sponge is thoroughly flushed and filled with a fresh charge of water at the same time that the edge of the sponge is cleaned by the flowing stream.

To reinstall the sponge assembly the sequence is reversed, that is, the sponge assembly is seated in side plate 91 with the squeegee roller 25 in place, thus establishing contact between the lower exposed edge 83 of the sponge and the surface of the squeegee roller. The cooperating side plate is added so that the roller is again captive, and the cartridge is then inserted upwardly and rearwardly into the receptacle until it is latched in a fully seated position. The prop 147 is swung rearwardly to its out-of-the-way position, following which the upper portion, or plenum, of the machine islowered into horizontal working position as shown in FIG. 1.

The drive motor 37, blower motor 53 and heaters 61, 62 are then turned on. The rotation of the roller 33 at the front end of the belt assembly rotates the lower squeegee roller 24 via gears -137. This causes the upper squeegee roller 25, which is frictionally engaged with the lower squeegee roller, to rotate so that the surface of the upper squeegee roller is both cleaned and wetted by the sponge 82. The lower squeegee roller24 is also wetted by running in contact with the roller 25.

With the blower assembly and heating elements turned on, warm air under slight pressure is forced into the plenum chamber 40 and outwardly through the pattern of orifices 70 on the bottom wall 41. This provides successive jets of warm air downwardly at right angles toward the belts 31, 32 which make up the belt assem bly.

As a wet print P is fed into the nip 26 in the entry way, the squeegee rollers 24, 25 take over" and cause the print to be squeegeed as it is passed rearwardly onto the belts 31. As has been stated, a print inserted into the machine may have a wide range of moisture content. A print may have standing beads of water on the emulsion side and a saturated paper backing. On the other hand, and especially where the print is of the RC type, it may have relatively little moisture content and if the print has been out of the final wash water an appreciable length of time there may be practically no water on the emulsion side and very little absorbed in the backing. Where a practically dry print is inserted into a drying machine where the squeegee rollers are in the initially dry condition, sticky stabilizer materials added in the final bath tend to stick to the roller surfaces. Moreover, bringing a dry squeegee roller into contact with the face of the print may effect the integrity of the relatively soft emulsion, and even lift off a portion of it, so that the appearance of the print suffers, aggravating the accumulation or build-up on the surfaces of the rollers. By constrast, it is found that where a uniform film of moisture is constantly applied to a squeegee roller, more specifically to a pair of squeegee rollers, prior to engagement by a print, the print, even when in nearly dry condition, is protected and isolated by the film of water which is interposed between the rollers and the print surfaces so that no build-up can occur. The protection provided by the auxiliary film of water is particularly important during the first few inches of movement of the print into the squeegee rollers since there is often insufficient moisture on the print, at that time, to form a protective puddle extending along the inlet nip. The orientation of the cartridge, extending upwardly as it does, inherently makes use of gravity to insure that the water in the sponge will tend to be concentrated along its lower edge so that a film of water will wet the squeegee rollers just as soon as they begin to move. This insures protective wetting even where the machine is started up after a prolonged period of idleness. The wiping of the upper squeegee roller by the wetted sponge also serves to remove from the squeegee roller any particles of lint or other foreign material which may tend to collect upon the surface so that the roller surface is constantly renewed and maintained in perfectly clean condition during a long run during which many hundreds of prints may be dried.

While the advantage of the present construction has been discussed in connection with RC prints, and particularly where such prints are in the nearly dry state, it is one of the further features of the invention that prints may be handled which are of other and more traditional materials, which are highly absorbent and have a larger amount of water to be initially disposed of. The excess water is, in any event, expressed at the inlet nip, running down into the drip tray 190 where it is largely evaporated by the circulating currents of warm air within the machine.

As the squeegeed print passes rearwardly in the machine upon the first set of belts 31, the impingement, upon the face of the print, by the warm air jets from the orifices 70 not only serves to dry the print but serves to hold it securely, for transport, against the belts. The rate of movement is tailored to the rate of flow and to temperature of the air so that drying is sure to occur by the time that the print reaches the rear portion of the machine. In a practical case the rate of belt movement may be between and inches per minute with a total air flow of between 120 and l cfm, with the air being within the temperature range of between 150 F and 165 F and with the orifices 70 tailored to produce a velocity which may be on the order of 240 inches per second;

BecaUse of the fact that the belts 31, 32 are spaced apart and because of the fact that exhaust takes place from the lower portion of the machine, the heated air not only strikes the face of the print but is circulated between adjacent prints and around the lateral edges so that heated air currents operate with a high degree of efficiency on the underside of each print. It is found that in the present design of the machine both the emulsion side and the backing are dried to proper degree, with the emulsion achieving a proper degree of hardness, by the time that a print reaches the rear portion of the machine ready for turnaround.

For purposes of turnaround the leading edge of the print is engaged in the nip 176 between the sets of belts 162, 172. While it is true that the belts 172 engage the emulsion side, the emulsion, by this time, can withstand direct contact without risk of damage, and the print is therefore passed between the sets of belts, about the cylindrical guide plate 161 and into the superstructure. The print is finally discharged between the rollers 164, 174 at the termination of the belt loops and is propelled through the discharge orifice 27 onto the receiving surface 28 in face down condition.

It is one of the features of the present construction that when servicing is necessary the upper portion 22 of the'machine, which contains the plenum, may be swung upwardly about the hinge to a completely upraised position, slightly beyond the vertical, as shown in FIG. 15,. with the superstructure serving as a backstop. With the machine in this condition free access is provided to the space between the side walls 141, 142 for inspection and maintenance. Because of movement beyond dead center, there is no danger of forward toppling when the operatoris wiping the belts or performing other maintenance within the machine. It may be noted that since the blower and heater are mounted in the base portion of the machine, rather than in the upper portion, raising of the plenum to the position shown in FIG. 15 is accompanied by disengagement or uncoupling of the air flow path. When the plenum is lowered back into its horizontal working position, the rear open end 44 of the plenum is automatically recoupled to the blower assembly and heaters.

It is one of the features of the present drying apparatus that the upper portion, or plenum, may be freely raised and lowered to provide biasing force between the squeegee rollers without requiring any latch or locking device to hold it in lowered position. The fact that the hinge 140 is located along the rear edge of the plenum means that the forwardly overhanging weight of the plenum and the cartridge which it includes is available for application to the upper squeegee roller. It is-one of the features of the construction that the cartridge, including the upper squeegee roller is movably mounted, in the present instance by hingeing, and biased downwardly by auxiliary biasing springs 126. This type of mounting distributes the force between the rollers more evenly along their length. Moreover, use of springs 126 enables the total biasing force to be optimized. There are two possibilities: The first is to use springs 126 of such stiffness or geometry that a point of equilibrium is reached in the springs with the full overhanging weight of the plenum applied between the squeegee rollers. The second possibility is to provide stops interposed in the path of downward movement of the plenum so that bottoming, in working position, occurs with the springs 126 only partially flexed so that the biasing force is at a predetermined level less than the overhanging weight. Either of these alternatives may be employed in a practical design. Where the hinged plenum structure is of light construction, not exerting sufiicient biasing force by reason of its overhanging weight, a latch may be used to hold it down against the reaction force of springs 126 without departing from the invention.

The present invention has been discussed in connection with a preferred embodiment in which the squee gee rollers are both resiliently surfaced with rubber or other elastomeric material having a durometer rating of 50-55 and in which water is employed as the dampening and cleansing medium. If desired, one of the squeegee rollers may be hard surfaced with primary reliance then placed upon the remaining resilient roller to provide the squeegee effect. Moreover, the liquid which wets the squeegee sponge may be an appropriate liquid other than water or water which is mixed with glycerine, alcohol, or some other suitable additive. Also, if desired, a cartridge similar to the cartridge 80 may be used in the lower portion of the machine having a sponge which is in wiping engagement upon the lower squeegee roller 24.

Preferably, fine pore cellulosic material is used for the sponge 82, such material being obtainable as a commercial item from E. I. duPont Co., Inc. or other suppliers. However, it will be understood that the term sponge as used herein is not limited to cellulose and that substantially any porous and water-receptive material may be used for this purpose, especially one which has resilience, in the wet state, to expand to fill the full space which is available within the cartridge and to provide sucking action to facilitate flushing when the portions 111, 112 of the shell are squeezed and released.

While the above described construction has particular utility in the drying of photographic prints, it will be apparent to one skilled in the art that the machine is equally suitable for drying other sheets where unwanted accumulations tend to occur on the inlet rollers and where it is necessary to avoid contact with the face of the sheet as the drying progresses.

The term blower has been used throughout to describe the means for creating the necessary movement of air. While the blower having an impeller of the usual squirrel-cage type is preferred, the term is intended to be a general one to include fans or blowers of any configuration. While the terms upper, lower, front and back have been used for convenience, it will be understood that these terms are relative and not absolute, for example, the machine may be rotated so that the entryway is at the side rather than at the front without departing from the invention. The term heating means as used herein refers to any means for raising the temperature of the moisture in the prints, including transfer of sensible heat to the prints from a suitable source or generation of heat locally in the body of the print by subjecting it to an alternating electric field by induction or the like resulting in internal generation of heat by eddy current or dielectric losses.

What I claim is:

1. In a dryer for photographic prints and the like, the combination comprising an enclosure of box-like construction having a front entryway, means for creating currents of heated air within the enclosure, a belt assembly including a motor in the enclosure for horizontal transport of a series of prints face up as the prints are acted upon by the currents of air, upper and lower squeegee rollers adjacent the entryway with the upper squeegee roller engaging the face of an inserted print, a cartridge extending the width of the entryway having means for journaling the upper squeegee roller, the cartridge defining an enclosed recess, a wetted sponge substantially filling the enclosed recess with the edge of the sponge in engagement with the upper squeegee roller, means for coupling the rollers to the motor so that the upper roller constantly wipes the sponge thereby to maintain the roller surface in a constantly and uniformly wetted condition in advance of insertion of prints into the entryway while removing any extraneous particles of foreign matter from the surface thereof.

2. In a dryer for photographic prints and the like, the combination comprising an enclosure of box-like construction having a lower portion and an upper portion and providing a front entryway, a transport assembly including a motor in the lower portion for horizontal transport of a print inserted face-up into the entry way, means in the upper portion for producing heat and for directing it downwardly in the direction of the transport assembly, a cartridge of elongated rectangular shape having enclosing side walls defining a central space and having a wetted sponge therein, an upper squeegee roller journaled adjacent the edge of the car tridge, the sponge having a projecting edge in wiping engagement with the upper squeegee roller and extending along the length thereof, means in the upper portion of the dryer for mounting the cartridge adjacent the entryway with the upper squeegee roller extending downwardly therefrom, a cooperating lower squeegee roller in the lower portion of the dryer rotationally coupled to the belt assembly for constant rotation therewith, the upper portion of the dryer having a horizontal hinge connection at its rear end with the lower portion so that the overhanging weight of the upper portion is in a direction to bias the upper squeegee roller against the lower squeegee roller for rotational driving of the upper squeegee roller so that the latter is constantly wetted and cleaned by the sponge, and means for permitting the cartridge to be manually withdrawn when servicing of the sponge is required.

3. In a dryer for photographic prints and the like, the combination comprising an enclosure of boxlike construction having a lower portion and an upper portion, means defining a horizontal entryway, a transport assembly in the lower portion having a driving motor for horizontally transporting a print which is inserted faceup into the entryway, means in the-upper portion for providing heated air and for discharging it downwardly in the direction of the transport assembly for drying the print and for holding it in contact therewith, a vertically extending pair of squeegee rollers at the entryway rotationally coupled to the motor for constant rotation, and means including a wiper having an associated porous reservoir having provision for presaturation with water for keeping the squeegee roller which contacts the face of the print constantly and uniformly wetted with a film of water in readiness for insertion of the print.

4. In a dryer for photographic prints and the like, the combination comprising an enclosure having an entryway, transport means including a motor in the enclosure for transporting a print fed into the entryway, means for heating the print to drive off moisture, the transport means having associated upper and lower squeegee roller means at the entryway rotationally coupled to the motor for constant rotation with one roller contacting the face of the print while the other roller contacts the back of the print, the roller means having a wetted wiper extending along the length thereof in wiping engagement to maintain a constant and uniform film of water thereon in readiness for insertion of the print thereby to insure that a clean film of water is interposed between the roller means and the print upon feeding of a print into the entryway, the wiper having an associated porous reservoir, the reservoir having provision for pre-charging with a body of water so that the wiper is effective to transfer a film of water to the roller means promptly upon rotation thereof even after a prolonged period of idleness.

5. In a dryer for photographic prints and the like, thecombination comprising an enclosure of box-like construction having a lower portion and an upper portion, the portions being openably secured together and defining an entryway, a transport assembly including a motor in the lower portion for horizontal transport of a print inserted face-up into the entryway, means in the upper portion for producing heated air and for discharging it downwardly in the direction of the transport assembly for drying of the print as well as for holding it in contact with the transport assembly, a hollow cartridge removably mounted in the upper portion and having an upper squeegee roller journaled therein which extends along the upper edge of the entryway, the lower portion having a lower cooperating squeegee roller journaled therein and extending along the lower edge of the entryway, the lower squeegee roller being rotationally coupled to the motor, a wetted sponge in the cartridge extending along the upper squeegee roller and having a working edge in wiping contact therewith for maintaining a substantially constant and uniform film of water on the upper squeegee roller in readiness for insertion of a print, and a drip pan under the lower squeegee roller for receiving excess ..water expressed from the print as it passes between the rollers.

6. The combination as claimed in claim in which the cartridge totally encloses the sponge to inhibit evaporation therefrom except from the working edge portion, the working edge portion being of reduced cross section.

7. The combination as claimed in claim 5 in which the transport assembly is made up of belts spaced to provide openings between them for circulation of air to the underside of the prints and means for vented discharge of air from the lower portion.

8. The combination as claimed in claim 5 in which a horizontal hinge connection is provided at the rear end of the upper portion of the dryer to pennit such upper portion to be swung upwardly thereby to permit access to the space between the upstanding'parallel side walls of the lower portion for servicing and the like and so that the overhanging weight of the upper portion is ef fective to bias the upper squeegee roller against the lower squeegee roller.

9. The combination as claimed in claim 8 in which the cartridge is mounted with respect to the upper portion of the dryer for vertical movement over a small range and in which a spring is interposed between the upper portion of the dryer and the cartridge for biasing the cartridge in a downward direction.

10. In a dryer for photographic prints and the like, the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having upstanding parallel side walls, a belt assembly comprised of a plurality of spaced generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber and having an associated blower and heating element for discharge of warm air into the plenum chamber, the bottom wall of the plenum chamber having a pattern of air discharge openings, the upper portion of the enclosure being dimensioned to fit in the space between the upstanding side walls of the lower portion so that the bottom wall thereof is spaced slightly above and generally parallel to the belt assembly so that the air from the discharge openings strikes the faces of a series of transported prints to dry the faces and to hold the prints securely against the belt assembly, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer and having a nip substantially alined with the belt assembly so that when prints are fed between the rollers any excess water thereon is expressed prior to passage of a print to the belt assembly, means for coupling the lower squeegee roller to the belt assembly for constant rotation therewith, and wetted means for wiping the surface of the upper squeegee roller for maintaining it in a constantly clean and wet condition in readiness for insertion of aprint.

11. The combination as claimed in claim 10 in which the upper portion of the dryer fits substantially flush with the upper edges of the upstanding side walls of the lower portion to provide a flat and continuous upper receiving surface and in which a turnaround is provided at the rear end of the belt assembly for discharging the prints forwardly onto the receiving surface.

12. In a dryer for photographic prints and the like, the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having upstanding parallel side walls and bearing an integral super-structure at the rear end thereof, a belt assembly comprised of a plurality of spaced generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber, the bottom wall of the plenum chamber having a pattern of air discharge openings arranged above the belt assembly, the upper portion of the enclosure being dimensioned to fit in the space between the upstanding sidewalls of the lower portion and just ahead of the superstructure, the upper portion of the dryer having a horizontal hinge connection at its rear end for enabling the upper portion to be upraised for access to the space between the upstanding walls and to be lowered between the walls into a working position, a blower at the rear of the lower portion for discharging air into the plenum chamber when the upper portion of the dryer is in its working position, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer so that when the upper portion of the dryer is in working position the rollers are brought together to form a nip which is substantially alined with the belt assembly and so that when a print is fed between the rollers any excess water thereonis expressed prior to passage of the print to the belt assembly, means for coupling the lowersqueegee roller to the belt assembly for constant rotation therewith, and means for keeping the upper squeegee roller constantly and uniformly wetted with a film of water as long as the upper portion of the dryer occupies its working position.

13. The combination as claimed in claim 12 in which turnaround means are provided at the rear end of the belt assembly for transporting the prints from the belt assembly around the blower and into the superstructure for discharge forwardly from the superstructure upon the presented surface of the upper portion of the dryer.

14. The combination as claimed in claim 13 in which the turnaround means includes a cylindrical guide surface which extends around the blower upwardly into the superstructure and having a belt following the guide surface, the belt being coupled for driving purposes to the belt assembly.

15. The combination as claimed in claim 13 in which the turnaround means includes a cylindrical guide surface which extends around the blower upwardly into the super structure and having a pair of belts following the guide surface, the belts being coupled for driving purposes to the belt assembly, the pair of belts having an inlet nip for engaging the leading edge of a print transported thereto by the horizontal belt assembly.

16. In a dryer for photographic prints and the like the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having an integral superstructure at the rear end thereof, a belt assembly comprised of a plurality of generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber having an air inlet opening in its rear wall, the bottom wall of the plenum chamber having a pattern of air discharge openings arranged above the belt assembly, the upper portion of the enclosure being dimensioned to fit conformingly in the space just ahead of the superstructure, the upper portion of the dryer having a horizontal hinge connection at its rear end for enabling the upper portion to be upraised in front of the superstructure for access to the space to the belt assembly and to be lowered into a horizontal working position, a blower in the lower portion of the dryer extending upwardly into the superstructure and having an inlet positioned for discharging of air into the inlet opening of the plenum chamber when the upper portion of the dryer is in its horizontal working position, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer so that when the upper portion of the dryer is in working position the rollers are brought together to form a nip which is substantially alined with the belt assembly and so that when a print is fed between the rollers any excess water thereon is expressed prior to passage of the print to the belt assembly, means for coupling the lower squeegee roller to the belt assembly for constant rotation therewith, and means including a sponge for keeping the upper squeegee roller constantly and uniformly wetted with a film of water as long as the upper and lower squeegee rollers are in rolling engagement with one another 17. In a dryer for photographic prints and the like, the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having an integral superstructure at the rear end thereof, a belt assembly comprised of a plurality of generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber having an air inlet opening in its rear wall and having a pattern of air discharge openings in its bottom wall, the upper portion of the enclosure being dimensioned to fit conformingly ahead of the superstructure in horizontal working position with the openings in the bottom wall spaced above the belt assembly, a blower within the superstructure having an outlet which registers with the inlet opening of the plenum chamber so that when the latter is in horizontal working position air is discharged into the plenum chamber and thence downwardly upon the prints conveyed by the belt assembly, means at the rear end of the belt assembly for transporting the prints upwardly about an angle of into the top portion of the superstructure from whence the prints are discharged forwardly on top of the machine, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer so that when the upper portion of the dryer is in working position the rollers are brought together to form a nip which is substantially alined with the belt assembly, means for coupling the squeegee rollers to the motor and means including a sponge for constant wiping of at least one of the squeegee rollers.

18. For use in a dryer for photographic prints and the like having a pair of driven cooperating squeegee rollers adjacent an entryway for expressing excess water from the prints and having means for transporting the prints while subjecting them to currents of heated air, a cleaning and moistening cartridge comprising, in combination, a pair of elongated side plates having peripheral flanges along the top edge and at the ends so that when the side plates are arranged with the peripheral flanges in mating edge-to-edge contact a box-like housing is formed having a central recess, bearing means associated with the end flanges for joumaling one of the squeegee rollers along the lower edge of the housing, a wetted sponge substantially filling the recess with its lower edge bearing upon the surface of the joumaled squeegee roller for constantly wetting and cleaning the surface as the roller is rotated in engagement with the cooperating squeegee roller.

19. The combination as claimed in claim 18 in which the sponge has a thin protective shell enclosing the same to inhibit evaporation of water therefrom and with the lower edge of the sponge projecting from the shell into wiping engagement with the roller.

20. The combination as claimed in claim 19 in which the end flanges on the side plates have cooperating semicircular cutouts for gripping the ends of the roller when the side plates are assembled together but permitting the sponge in its shell to be removed when the side plates are separated from one another for periodic rinsing and recharging with water. I

21. For use in a dryer for photographic prints and the like having a pair of driven cooperating squeegee rollers adjacent an entryway for expressing excess water on the prints and having means for transporting the prints while subjecting them to currents of heated air, a cleaning and moistening cartridge comprising, in combination, a sponge of elongated rectangular shape made of resilient material having a working edge which is presented to one of the squeegee rollers for constantly wetting and wiping the same, a shell substantially enclosing the sponge, said shell being of multi-part construction including side walls having a normal spacing but which may be manually squeezed toward one another for squeezing of residual water out of the sponge, the sponge substantially filling the space between the side walls so that the natural resilience of the sponge restores the side walls to their normal spacing accompanied by sucking action for recharging of the sponge with water.

22. The combination as claimed in claim 21 in which the cartridge includes a rigid outer housing for enclosing and protecting the shell when it is mounted in the dryer, the housing including means for joumaling one of the squeegee rollers in wiping engagement with the working edge of the sponge.

23. In a dryer for photographic prints and the like, the combination comprising a hollow base structure having side walls, a superimposed box-like plenum, means defining an entryway between the plenum and the base portion, a belt assembly including a motor in the base portion for horizontal transport of a print inserted face-up into the entryway, means for producing heated air under slight pressure in the plenum, the lower wall of the plenum having a pattern of apertures for downward discharge of the air in jets directed toward the belt assembly for drying a print as well as for holding it in contact with the belt assembly, a hollow cartridge retractably mounted in the forward portion of the plenum and having an upper squeegee roller journaled therein which extends along the upper edge of the entryway, the base portion having a lower cooperating squeegee roller journaled therein and extending along the lower edge of the entryway, the lower squeegee roller being rotationally coupled to the motor, a wetted sponge in the cartridge extending along the upper squeegee roller and having a working edge in wiping contact therewith for maintaining a substantially constant and uniform film of water on the upper squeegee roller in readiness for insertion of a print, a

drip pan in the form of a drawer inserted into the bottom of the base and covering a substantial portion of the area thereof for constant evaporation of the liquid 7 received from the squeegee rollers, the drawer having a front panel integral therewith enclosing the front of the base, the plenum being horizontally hinged along its rear edge to the base so that by swinging the plenum upwardly and pulling the drawer forwardly the squeegee rollers are exposed for retraction of the cartridge holding the upper squeegee roller.

24. The combination as claimed in claim 23 in which the cartridge is mounted in the front end of the plenum for removal downwardly and in which a prop is pro vided between the base and plenum shiftable between inactive and active positions for temporarily supporting the plenum in a shallow upwardly angled position about its hinge connection for facilitating removal of the cartridge.

25. In a dryer for photographic prints and the like, the combination comprising a hollow base structure having side walls, a box-like plenum chamber horizontally superimposed thereon, means defining an entryway between the plenum and the base, a belt assembly including a motor in the base for horizontal transport of a print inserted face up into the entryway, a blower assembly mounted in the rear portion of the base hav ing an air inlet and having an air outlet, the lower wall of the plenum having a pattern of apertures for downward discharge of air from the plenum in the form of jets for drying the print as well as [holding it in contact with the belt assembly, lower and upper squeegee rollers at the entryway respectively journaled in the front edges of the base and plenum, the lower squeegee roller being coupled for rotation to the belt assembly, the plenum having a hinge connection with the base structure along a horizontal transverse axis which lies at the rear of the plenum and adjacent its upper surface so that the plenum may be rocked from horizontal position to vertical position for access to the base accompanied by separation of the squeegee rollers, the rear end of the plenum having an air inlet opening registering with the outlet of the blower assembly so that an air passage between the blower assembly and the plenum is automatically established when the plenum is lowered into horizontal working position. 

1. In a dryer for photographic prints and the like, the combination comprising an enclosure of box-like construction having a front entryway, means for creating currents of heated air within the enclosure, a belt assembly including a motor in the enclosure for horizontal transport of a series of prints face up as the prints are acted upon by the currents of air, upper and lower squeegee rollers adjacent the entryway with the upper squeegee roller engaging the face of an inserted print, a cartridge extending the width of the entryway having means for journaling the upper squeegee roller, the cartridge defining an enclosed recess, a wetted sponge substantially filling the enclosed recess with the edge of the sponge in engagement with the upper squeegee roller, means for coupling the rollers to the motor so that the upper roller constantly wipes the sponge thereby to maintain the roller surface in a constantly and uniformly wetted condition in advance of insertion of prints into the entryway while removing any extraneous particles of foreign matter from the surface thereof.
 2. In a dryer for photographic prints and the like, the combination comprising an enclosure of box-like construction having a lower portion and an upper portion and providing a front entryway, a transport assembly including a motor in the lower portion for horizontal transport of a print inserted face-up into the entry way, means in the upper portion for producing heat and for directing it downwardly in the direction of the transport assembly, a cartridge of elongated rectangular shape having enclosing side walls defining a central space and having a wetted sponge therein, an upper squeegee roller journaled adjacent the edge of the cartridge, the sponge having a projecting edge in wiping engagement with the upper squeegee roller and extending along the length thereof, means in the upper portion of the dryer for mounting the cartridge adjacent the entryway with the upper squeegee roller extending downwardly therefrom, a cooperating lower squeegee roller in the lower portion of the dryer rotationally coupled to the belt assembly for constant rotation therewith, the upper portion of the dryer having a horizontal hinge connection at its rear end with the lower portion so that the overhanging weight of the upper portion is in a direction to bias the upper squeegee roller against the lower squeegee roller for rotational driving of the upper squeegee roller so that the latter is constantly wetted and cleaned by the sponge, and means for permitting the cartridge to be manually withdrawn when servicing of the sponge is required.
 3. In a dryer for photographic prints and the like, the combination comprising an enclosure of boxlike construction having a lower portion and an upper portion, means defining a horizontal entryway, a transport assembly in the lower portion having a driving motor for horizontally transporting a print which is inserted faceup into the entryway, means in the upper portion for providing heated air and for discharging it downwardly in the direction of the transport assembly for drying the print and for holding it in contact therewith, a vertically extending pair of squeegee rollers at the entryway rotationally coupled to the motor for constant rotation, and means including a wiper having an associated porous reservoir having provision for pre-saturation with water for keeping the squeegee roller which contacts the face of the print constantly and uniformly wetted with a film of water in readiness for insertion of the print.
 4. In a dryer for photographic prints and the like, the combination comprising an enclosure having an entryway, transport means including a motor in the enclosure for transporting a print fed into the entryway, means for heating the print to drive off moisture, the transport means having associated upper and lower squeegee roller means at the entryway rotationally coupled to the motor for constant rotation with one roller contacting the face of the print while the othEr roller contacts the back of the print, the roller means having a wetted wiper extending along the length thereof in wiping engagement to maintain a constant and uniform film of water thereon in readiness for insertion of the print thereby to insure that a clean film of water is interposed between the roller means and the print upon feeding of a print into the entryway, the wiper having an associated porous reservoir, the reservoir having provision for pre-charging with a body of water so that the wiper is effective to transfer a film of water to the roller means promptly upon rotation thereof even after a prolonged period of idleness.
 5. In a dryer for photographic prints and the like, the combination comprising an enclosure of box-like construction having a lower portion and an upper portion, the portions being openably secured together and defining an entryway, a transport assembly including a motor in the lower portion for horizontal transport of a print inserted face-up into the entryway, means in the upper portion for producing heated air and for discharging it downwardly in the direction of the transport assembly for drying of the print as well as for holding it in contact with the transport assembly, a hollow cartridge removably mounted in the upper portion and having an upper squeegee roller journaled therein which extends along the upper edge of the entryway, the lower portion having a lower cooperating squeegee roller journaled therein and extending along the lower edge of the entryway, the lower squeegee roller being rotationally coupled to the motor, a wetted sponge in the cartridge extending along the upper squeegee roller and having a working edge in wiping contact therewith for maintaining a substantially constant and uniform film of water on the upper squeegee roller in readiness for insertion of a print, and a drip pan under the lower squeegee roller for receiving excess water expressed from the print as it passes between the rollers.
 6. The combination as claimed in claim 5 in which the cartridge totally encloses the sponge to inhibit evaporation therefrom except from the working edge portion, the working edge portion being of reduced cross section.
 7. The combination as claimed in claim 5 in which the transport assembly is made up of belts spaced to provide openings between them for circulation of air to the underside of the prints and means for vented discharge of air from the lower portion.
 8. The combination as claimed in claim 5 in which a horizontal hinge connection is provided at the rear end of the upper portion of the dryer to permit such upper portion to be swung upwardly thereby to permit access to the space between the upstanding parallel side walls of the lower portion for servicing and the like and so that the overhanging weight of the upper portion is effective to bias the upper squeegee roller against the lower squeegee roller.
 9. The combination as claimed in claim 8 in which the cartridge is mounted with respect to the upper portion of the dryer for vertical movement over a small range and in which a spring is interposed between the upper portion of the dryer and the cartridge for biasing the cartridge in a downward direction.
 10. In a dryer for photographic prints and the like, the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having upstanding parallel side walls, a belt assembly comprised of a plurality of spaced generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber and having an associated blower and heating element for discharge of warm air into the plenum chamber, the bottom wall of the plenum chamber having a pattern of air discharge openings, the upper portion of the enclosure being dimensioned to fit in the space between the upstanding side walls of the lower portion so that the bottom wall thereof is spaced slightly above and generally parallel to the belt assembly so that the air from the discharge openings strikes the faces of a series of transported prints to dry the faces and to hold the prints securely against the belt assembly, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer and having a nip substantially alined with the belt assembly so that when prints are fed between the rollers any excess water thereon is expressed prior to passage of a print to the belt assembly, means for coupling the lower squeegee roller to the belt assembly for constant rotation therewith, and wetted means for wiping the surface of the upper squeegee roller for maintaining it in a constantly clean and wet condition in readiness for insertion of a print.
 11. The combination as claimed in claim 10 in which the upper portion of the dryer fits substantially flush with the upper edges of the upstanding side walls of the lower portion to provide a flat and continuous upper receiving surface and in which a turnaround is provided at the rear end of the belt assembly for discharging the prints forwardly onto the receiving surface.
 12. In a dryer for photographic prints and the like, the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having upstanding parallel side walls and bearing an integral superstructure at the rear end thereof, a belt assembly comprised of a plurality of spaced generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber, the bottom wall of the plenum chamber having a pattern of air discharge openings arranged above the belt assembly, the upper portion of the enclosure being dimensioned to fit in the space between the upstanding sidewalls of the lower portion and just ahead of the superstructure, the upper portion of the dryer having a horizontal hinge connection at its rear end for enabling the upper portion to be upraised for access to the space between the upstanding walls and to be lowered between the walls into a working position, a blower at the rear of the lower portion for discharging air into the plenum chamber when the upper portion of the dryer is in its working position, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer so that when the upper portion of the dryer is in working position the rollers are brought together to form a nip which is substantially alined with the belt assembly and so that when a print is fed between the rollers any excess water thereon is expressed prior to passage of the print to the belt assembly, means for coupling the lower squeegee roller to the belt assembly for constant rotation therewith, and means for keeping the upper squeegee roller constantly and uniformly wetted with a film of water as long as the upper portion of the dryer occupies its working position.
 13. The combination as claimed in claim 12 in which turnaround means are provided at the rear end of the belt assembly for transporting the prints from the belt assembly around the blower and into the superstructure for discharge forwardly from the superstructure upon the presented surface of the upper portion of the dryer.
 14. The combination as claimed in claim 13 in which the turnaround means includes a cylindrical guide surface which extends around the blower upwardly into the superstructure and having a belt following the guide surface, the belt being coupled for driving purposes to the belt assembly.
 15. The combination as claimed in claim 13 in which the turnaround means includes a cylindrical guide surface which extends around the blower upwardly into the super structure and having a pair of belts following the guide surface, the belts being coupled for driving purposes to the belt assembly, the pair of belts having an inlet nip for engaging the leadinG edge of a print transported thereto by the horizontal belt assembly.
 16. In a dryer for photographic prints and the like the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having an integral superstructure at the rear end thereof, a belt assembly comprised of a plurality of generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber having an air inlet opening in its rear wall, the bottom wall of the plenum chamber having a pattern of air discharge openings arranged above the belt assembly, the upper portion of the enclosure being dimensioned to fit conformingly in the space just ahead of the superstructure, the upper portion of the dryer having a horizontal hinge connection at its rear end for enabling the upper portion to be upraised in front of the superstructure for access to the space to the belt assembly and to be lowered into a horizontal working position, a blower in the lower portion of the dryer extending upwardly into the superstructure and having an inlet positioned for discharging of air into the inlet opening of the plenum chamber when the upper portion of the dryer is in its horizontal working position, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer so that when the upper portion of the dryer is in working position the rollers are brought together to form a nip which is substantially alined with the belt assembly and so that when a print is fed between the rollers any excess water thereon is expressed prior to passage of the print to the belt assembly, means for coupling the lower squeegee roller to the belt assembly for constant rotation therewith, and means including a sponge for keeping the upper squeegee roller constantly and uniformly wetted with a film of water as long as the upper and lower squeegee rollers are in rolling engagement with one another
 17. In a dryer for photographic prints and the like, the combination comprising an enclosure having a lower portion and an upper portion, the lower portion including a hollow base having an integral superstructure at the rear end thereof, a belt assembly comprised of a plurality of generally horizontally extending belts mounted in the hollow base and having a drive motor, the upper portion of the dryer being of box shape defining a plenum chamber having an air inlet opening in its rear wall and having a pattern of air discharge openings in its bottom wall, the upper portion of the enclosure being dimensioned to fit conformingly ahead of the superstructure in horizontal working position with the openings in the bottom wall spaced above the belt assembly, a blower within the superstructure having an outlet which registers with the inlet opening of the plenum chamber so that when the latter is in horizontal working position air is discharged into the plenum chamber and thence downwardly upon the prints conveyed by the belt assembly, means at the rear end of the belt assembly for transporting the prints upwardly about an angle of 180* into the top portion of the superstructure from whence the prints are discharged forwardly on top of the machine, lower and upper squeegee rollers mounted along the front edge of the belt assembly in the respective portions of the dryer so that when the upper portion of the dryer is in working position the rollers are brought together to form a nip which is substantially alined with the belt assembly, means for coupling the squeegee rollers to the motor and means including a sponge for constant wiping of at least one of the squeegee rollers.
 18. For use in a dryer for photographic prints and the like having a pair of driven cooperating squeegee rollers adjacent an entryway for expressing excess water from the prints and having means for transporting the prints while subjecting them to currents of heated aIr, a cleaning and moistening cartridge comprising, in combination, a pair of elongated side plates having peripheral flanges along the top edge and at the ends so that when the side plates are arranged with the peripheral flanges in mating edge-to-edge contact a box-like housing is formed having a central recess, bearing means associated with the end flanges for journaling one of the squeegee rollers along the lower edge of the housing, a wetted sponge substantially filling the recess with its lower edge bearing upon the surface of the journaled squeegee roller for constantly wetting and cleaning the surface as the roller is rotated in engagement with the cooperating squeegee roller.
 19. The combination as claimed in claim 18 in which the sponge has a thin protective shell enclosing the same to inhibit evaporation of water therefrom and with the lower edge of the sponge projecting from the shell into wiping engagement with the roller.
 20. The combination as claimed in claim 19 in which the end flanges on the side plates have cooperating semicircular cutouts for gripping the ends of the roller when the side plates are assembled together but permitting the sponge in its shell to be removed when the side plates are separated from one another for periodic rinsing and recharging with water.
 21. For use in a dryer for photographic prints and the like having a pair of driven cooperating squeegee rollers adjacent an entryway for expressing excess water on the prints and having means for transporting the prints while subjecting them to currents of heated air, a cleaning and moistening cartridge comprising, in combination, a sponge of elongated rectangular shape made of resilient material having a working edge which is presented to one of the squeegee rollers for constantly wetting and wiping the same, a shell substantially enclosing the sponge, said shell being of multi-part construction including side walls having a normal spacing but which may be manually squeezed toward one another for squeezing of residual water out of the sponge, the sponge substantially filling the space between the side walls so that the natural resilience of the sponge restores the side walls to their normal spacing accompanied by sucking action for recharging of the sponge with water.
 22. The combination as claimed in claim 21 in which the cartridge includes a rigid outer housing for enclosing and protecting the shell when it is mounted in the dryer, the housing including means for journaling one of the squeegee rollers in wiping engagement with the working edge of the sponge.
 23. In a dryer for photographic prints and the like, the combination comprising a hollow base structure having side walls, a superimposed box-like plenum, means defining an entryway between the plenum and the base portion, a belt assembly including a motor in the base portion for horizontal transport of a print inserted face-up into the entryway, means for producing heated air under slight pressure in the plenum, the lower wall of the plenum having a pattern of apertures for downward discharge of the air in jets directed toward the belt assembly for drying a print as well as for holding it in contact with the belt assembly, a hollow cartridge retractably mounted in the forward portion of the plenum and having an upper squeegee roller journaled therein which extends along the upper edge of the entryway, the base portion having a lower cooperating squeegee roller journaled therein and extending along the lower edge of the entryway, the lower squeegee roller being rotationally coupled to the motor, a wetted sponge in the cartridge extending along the upper squeegee roller and having a working edge in wiping contact therewith for maintaining a substantially constant and uniform film of water on the upper squeegee roller in readiness for insertion of a print, a drip pan in the form of a drawer inserted into the bottom of the base and covering a substantial portion of the area thereof for constant evaporation of the liquid reCeived from the squeegee rollers, the drawer having a front panel integral therewith enclosing the front of the base, the plenum being horizontally hinged along its rear edge to the base so that by swinging the plenum upwardly and pulling the drawer forwardly the squeegee rollers are exposed for retraction of the cartridge holding the upper squeegee roller.
 24. The combination as claimed in claim 23 in which the cartridge is mounted in the front end of the plenum for removal downwardly and in which a prop is provided between the base and plenum shiftable between inactive and active positions for temporarily supporting the plenum in a shallow upwardly angled position about its hinge connection for facilitating removal of the cartridge.
 25. In a dryer for photographic prints and the like, the combination comprising a hollow base structure having side walls, a box-like plenum chamber horizontally superimposed thereon, means defining an entryway between the plenum and the base, a belt assembly including a motor in the base for horizontal transport of a print inserted face up into the entryway, a blower assembly mounted in the rear portion of the base having an air inlet and having an air outlet, the lower wall of the plenum having a pattern of apertures for downward discharge of air from the plenum in the form of jets for drying the print as well as holding it in contact with the belt assembly, lower and upper squeegee rollers at the entryway respectively journaled in the front edges of the base and plenum, the lower squeegee roller being coupled for rotation to the belt assembly, the plenum having a hinge connection with the base structure along a horizontal transverse axis which lies at the rear of the plenum and adjacent its upper surface so that the plenum may be rocked from horizontal position to vertical position for access to the base accompanied by separation of the squeegee rollers, the rear end of the plenum having an air inlet opening registering with the outlet of the blower assembly so that an air passage between the blower assembly and the plenum is automatically established when the plenum is lowered into horizontal working position. 